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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /vendor/once_cell/examples/bench.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/once_cell/examples/bench.rs')
-rw-r--r-- | vendor/once_cell/examples/bench.rs | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/vendor/once_cell/examples/bench.rs b/vendor/once_cell/examples/bench.rs new file mode 100644 index 000000000..e6801258a --- /dev/null +++ b/vendor/once_cell/examples/bench.rs @@ -0,0 +1,28 @@ +use std::mem::size_of; + +use once_cell::sync::OnceCell; + +const N_THREADS: usize = 32; +const N_ROUNDS: usize = 100_000_000; + +static CELL: OnceCell<usize> = OnceCell::new(); + +fn main() { + let start = std::time::Instant::now(); + let threads = + (0..N_THREADS).map(|i| std::thread::spawn(move || thread_main(i))).collect::<Vec<_>>(); + for thread in threads { + thread.join().unwrap(); + } + println!("{:?}", start.elapsed()); + println!("size_of::<OnceCell<()>>() = {:?}", size_of::<OnceCell<()>>()); + println!("size_of::<OnceCell<bool>>() = {:?}", size_of::<OnceCell<bool>>()); + println!("size_of::<OnceCell<u32>>() = {:?}", size_of::<OnceCell<u32>>()); +} + +fn thread_main(i: usize) { + for _ in 0..N_ROUNDS { + let &value = CELL.get_or_init(|| i); + assert!(value < N_THREADS) + } +} |